Carrier-current system



Patented Dec, 31., 1929 l y UNITED STATES* PATENT OFFICE WALTER R. G. BA'KER, OF SCHENECTADY, NEW YORK, ASS-IGNOR T0 ,GENERAL ELECTRIC COMPANY, A CORPORATION F NEW YORK CARRIER-CURRENT SYSTEM Application-filed yApril 24, 192,5. Serial 110925,644.

My present invention relates to signaling systems, and more particularly to signaling' systems of the carrier current type in, whleh high frequency signaling currents are conducted over wires.

In many carrier current installationsthe various circuits radiating from the power house or switching station are not metallically connected. While it might in general be thought desirable to connect all coupling conductors together and then run the lead-in wire direct to the carrier equipment, this method has the distinct disadvantage that the entire system must always be charged by the carrier current.

It is an object of my invention to provide a carrier current system having a selectively controlled indicating device normallyconnected to each line of the system, and selec- -tively controlled communication apparatus normally disconnected from each line of the syste1n. With this arrangement, when a call is indicated on any one line of the system, the communication apparatus maybe connected to that one line alone. At the same time the indicatino device may be disconnected from the line ori/er which the call has been transmitted,

but will remain connected to the other lines of the system. In this manner several stations are permitted to call at the same time' giving an arrangement which is particularly desirable when the system is extended to cover inter-system work.

The novel features which I believe to be characteristic ofV my invention are set forth with part-icularity in the appended claims. My invention itself, however, both as to its organization and method of operation will vbest be understood by reference to. the following disclosure taken in connection with the accompanying drawing, in which the figure shows a circuit organization whereby my 1nvention/,fmay be carried into effect.

Referring to the drawing I have indicated at 1, 2 and 3 a plurality of coupling conducl tors. adapted to -be associated wlth a corre-- 50 transmitter 4,- a duplex carrier receiver 5,

spending number of wires of a system of disl and a telephone 38, isnormally disconnected from the system, but is adapted to be selectively connected to the coupling conductors by means of switches 6, 7 and 8. The switches are operated by means of a plurality of solenoids 9, 10 and 11, supplied by a common source of energy 12, and controlled by switches or keys 13, 14 and 15 respectively.

The calling apparatus comprises a selector notching relay 16, which may, for example, be of the'type described in Patent No. 865,536 Scribner and Enochs 1907, and an indicating drop and bell arrangement 17 normally connected to conductors 1, 2 and 3 by means of a plurality of switches 18, 19 and 20. The 65 latter switches are operated by a plurality of solenoids 21, 22 and 23, supplied from a common source of energy 24, and selectively controlled by a plurality of switches 25, 26 and 27.

The indicating device 17 comprises a plurality of switches 28, 29 and 30l in circuit with a plurality of solenoids 31, 32 and 33 respectively. The solenoids are supplied from a source of energy 34 and control the 75 operation of indicating dropsV and bells 35, 36 and 37.

.The operation of the device is as follows When a call comes in over the coupling con.- ductor 1 t-he impulses pass through switch 18 80 and thewinding of selector relay 16. The selector relay is notched up to a pointwhere contact 28 is closed, operating in this manner the indicating bell and drop 35. The operator noting that the indicator 35 has been 85 operated depres'ses the key or switch 25 energizing solenoid 21 to open switch 18 and deenergize the selector relay. Atthe same time the operator depresses the key or switch 15 thereby energizing coil 9 and closing switch 6 to connect the communication apparatus to the coupling conductor. v

If the local station wishes to send out a call over coupling conductor 1 the operator 95 depresses key 15 which closes a circuit through coil 9 to operate switch 6. The duplex carrier and receiver are then connected to the coupling conductor. At the time key 15 is depressed key 25 may be operated to 100 open contact 18 to disconnect the indicating device from coupling conductor 1.

lIVhile separate keysare shown energizing the two coils associated With any one coupling conductor, obviously both coils may be arranged to be operated by one vkey only il desired. For example, coils 9 and 2l might be connected either in series or in parallel so that when key 15 is depressed switch 6 will be closed and switch 18 opened.

lVhen any one line is in operation the signaling system Will, of course, be disconnected from that one line. The other lines remain connected to the signaling system so that calls may be indicated on any line except the line Which is at that time in operation'.

By the term coupling conductor7 I mean any conductor which may be employed to electrostatically connect carrier equipment to a system of distribution, or the like. Vhile I have shown coupling Wires adapted to connect the carrier equipment to a system. of distribution, obviously, coupling condensers may be employed instead if desired. Each conductor 1, 2 and 3 would then be connected to one of the plates of a coupling condenser while the other plates of the condensers Would be connected to the system of distribution.

While I have shown a carrier system operated from phase to ground, it is, of course, obvious that the system Will operate equally Well interphase employing either coupling condensers, or coupling conductors as shown. Various modifications of my device will readily suggest themselves to persons skilled in the art Without departing from the scope of my'invention as set forth in theappended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A-carrier current signaling system comprising a plurality of coupling conductors,

communication apparatus normally disconnected from said conductors, a plurality of indicating devices, each indicating device corresponding to one of said coupling conductors, a single means normally connected to all of said conductors for selectively actuating said indicating devices, and means for connecting the communication apparatus to one of said conductors and for disconnecting said single selective actuating means from that conductor only.

2. A carrier current signaling system comprising a plurality of coupling conductors, communication apparatus normally disconnected from said conductors, a plurality of indicating devices, each indicating device corresponding to one of said conductors, a single-means normally connected to all of said conductors for selectively actuatmgsald indicating devices and means for selectively connecting said communicatlon apparatus to ductors, a single means normally connected to all of said conductors for selectively actuating said indicating devices, means for selectively connecting said communication apparatus to said conductors and means forselectively disconnecting said single selective actuating means from any one of said conductors. i i

4. A carrier current signaling system com- Iprising a plurality of coupling conductors,

communication apparatus normally disconnected from said conductors, a plurality of indicating devices, corresponding to one of said coupling conductors, a single means' normally connected to all of said conductors for selectively actuating said indicating devices, means 'for selectively connecting said communication apeach indicating device paratus to any one of said conductors and for maintaining said communicating apparatus disconnected from the remaining conductors, and means for disconnecting-said single selective actuating means from sai-d one conductor and for maintaining'said single means conmeted to the remaining conductors.

' carrier current signaling system comprlsmg a plurality of coupling conductors, communication apparatus normally disconnected from said conductors, a plurality of indicating devices, each device correspondlng to one of said coupling conductors, a single means normally connected to all of said conductors for selectively actuating said indicating devices, and means for selectively connecting said communication apparatus to any one of said conductors and for disconnecting said single selective actuating means from said one conductor only.

In witness whereof, I have hereunto set my hand this 23d dayof April, 1925.

WALTER R. G. BAKER. 

